Separate Chemistry 5.10 Flashcards
Suggest two ways in which Humans use the Earth’s resources.
Any two from:
warmth
shelter
food
transport
What is meant by the term ‘sustainable development’?
Development that meets the needs of current generations without compromising the ability of future generations to meet their own needs.
Give one example of a natural product that has been supplemented by, or replaced by, agricultural or synthetic products.
Suggestions include:
- Man made polymers have replaced natural rubber in a number of uses (e.g. car tyres)
- Concrete has replaced natural stone in some buildings
- Manure replaced by artificial fertilisers
What is potable water?
Water that is safe to drink.
Is potable water pure water?
No, because it contains dissolved substances
What two things must drinking water have low levels of?
- Dissolved salts
- Microbes
Describe how potable water is produced in the UK.
- Choose an appropriate source of fresh water
- Passing the water through the filter beds
- Sterilising the water
Name the three different sterilising agents that can be used to make potable water.
- Chlorine
- Ozone
- Ultraviolet light
Name two processes that can be used to desalinate water.
- Distillation
- Reverse Osmosis
Name the process by which salt is removed from water.
Desalination
Why does industrial waste water need treatment before being released into the environment?
To remove organic matter and harmful chemicals
Why does sewage and agricultural waste water need treatment before being released into the environment?
To remove organic matter and harmful microbes
Describe the four main stages in the process of sewage treatment
- Screening and grit removal
- Sedimentation to produce sewage sludge and effluent
- Anaerobic digestion of sewage sludge
- Aerobic biological treatment of effluent
Higher Q. Why are new ways of extracting copper from low-grade ores needed?
High grade copper ores are running out.
Higher Q. What big advantage do phytomining and bioleaching have over traditional copper mining methods?
These methods do not involve digging, moving and disposing of large amounts of rock.
Higher Q. Describe the main stages in the phytomining process.
- Plants are grown on low-grade copper ores
- Plants absorb copper compounds
- Plants are harvested then burned
- Ash contains metal compounds
*Then electrolysis or displacement may be used to remove copper from the ash.
Higher Q. How does bioleaching work?
Bacteria produce leachate solutions that contain metal compounds
*Then electrolysis or displacement may be used to remove copper from the ash.
Higher Q. What two methods can be used to extract the copper from copper compounds after phytomining and bioleaching?
- Electrolysis
- Displacement using scrap iron
What are the four stages of a product’s life that are assessed by Life Cycle Assessments (LCAs)?
- Extracting and processing raw materials
- Manufacturing and packaging
- Use and operation during its lifetime
- Disposal at the end of its useful life (including transport and distribution at each stage)
What effects are difficult to predict by Life Cycle Assessments (LCAs), making them a little subjective?
Pollutant effects
Name three materials that are produced from limited raw materials.
Any three from:
metals, glass, building materials, clay ceramics, plastics
What are the four main advantages of reusing and recycling materials?
- Conserving limited resources
- Conserving energy
- Reducing waste (e.g. in landfill)
- Reducing environmental impacts
How are glass bottles recycled?
They are crushed and melted to make different glass products.
How are metals recycled?
They are melted and recasted or reformed into different products.